Finned insulator



Oct. 3, 1961 J. H; MEIER mmm: INSULATOR Filed Jan. 27, 1959 v 03,022 aFINNED INSULATO Jean Henri Meier, 'hi-bes, France, ssignor to CompagieGenerale d'EIeetro-Ce'amlqe, Paris, Seine,

France, a company of France y Filed Jan. 27, 1959, Se-. No. e V Clalmspriority, application France Mar. 1, 1958 3 Cllms. (CI. 174-211) Theinvention concerns improvements relating to self-` cleaning high-tensioninsulators, that is to say, insulators which are automaticallyself-cleaned by rain water, having` one or more vertical cylinder.

In the French patent application, February z, 1957, for "FinnedInsulator, the applicants have proposed to improve the behaw'our of suchinsulators under impulse voltages by providing the edge of the fin orrib with a flange projecting on both faces.

The present invention has for its object the improvement of theresistance of these insulators to tracking in a contaminated atmosphere.

To this end, according to the invention, one prow'desp on thei one faceof the helical fin or on the one and the other face of this fin, aprotuberance situated between the cylinder of the insulator 'and thefree edgesof the fin.

There may be more than one protuberance on the fins or ribs'disposedhelically along a p shown that the insulator with z g stacked fins ofthe normal type withstood 10 cycles whilstthe'insulator with the helicalfin improved as described with respect to FIG. 1 withstood cycles beforetracking.

FIG. 2 shows a simplified embodiment in which ai single, protuberance 6is provided on the upper face of the fin between the post 3 of theinsulator and the free edge of the fin. v

a This intermediate protuberance may also be provided onthe lower faceof the fin as at 7 in FIG. 1 or, again, such a protuberance may beprovided on each face ot the fin or theone ,or the other face or `bothmay bear same face of the fin. It is advantageous for one of theprotuberances to be at the edge of the fin, and the preferredcombination is that in which the edge of the fin bears a protuberance oneach face with at least one intermediate protuberance, because one thenimproves at the same time the behaviour under Shock voltages of thebehaviour in contaminated atmospheres.

The following description in conjunction with the accompanying drawings,given by way of non-limitative i example, shows the different, featuresof the invention and the way in which they are realised, allarrangernents, as is clear from the text as wellas the figures, lyingwithin the scope of the present invention.

FIG. 1 is a view in elevation, partially sectioned, of one preferredembodiment of an insulator according to the invention.

FIG. 2 is a partial sectional view embodiment.

In the embodiment according to FIG. 1, the insulator according to theinvention is constituted basically by an of a simplified insulating body1 sealed at its extremities' into two metali lic caps 2; the insulatingbody is constituted by a cylindrical post 3 hearing a fin in the form'of a helical rib 4. The fin 4 is provided at its extremitywith a flange5 projecting from the one and the other face of the fin as described inthe patent application referred to above` Moreover, the fin is providedwith swellings or protuberances 6 and 7 on the oneand the other face.

Tests carried out on insulators of the support" type so constituted andof general dimensions: 756 mm., diameter 180 mm. for insulator withhelical fins, diameter 210 mm. for an insulator with fins of the usualtype, subjected to oycles of contamination comprising, under normalservice voltage, an exposure 'to a dusty atmosphere for two hoursfollowed by an exposure to a saline mist for four hours under stn'ctlydefined conditions, have several protuberances, this lattedispositionbeing equally applicable in the case where there is a terminalprotuberance on the edge of the fin as at 5 in For reason ofsimplification the examples shown bear only one helical fin. It ishowever clear that the invention is equally applicable when the numberof helical fins is greaterthan one. Moreover, the invention isapplicable whether the post of the insulator is solid or hollow, whetherit transmits forces either in compression or tension or only serves as aprotective envelope for electrical conductors without mechanical action,and whether the head of the fin is inclined to the longitudinal axis ofthe insulator or is perpendicular to its axs as is shown in FIGS. 1 and2.

lt is preferable as shown in FIG. 1 that the section of the fin in anaxial view should be such that the line delimiting the space between thetwo faces of adjacent turns, a-b-c-d, a'-b'-c'-d' possesses an axis ofsymmetry 0-0'. In efiect, it is then possible to manufacture theinsulator by turning.

e It is sufiicient to turn a fresh cylinder of ceramic paste (that is tosay, an unfired blank of a ceramic material the rib intermediate saidinsulator body and the peripheral edge of the rib and extendingcoaxially with said peripheral edge of the rib.

2. A self-washing insulator comprising an elongated body of dielectricmaterial having a helical rib integral thereon extending :along thelength of said body, the rib having an upper and a lower face and on atleast one face' thereof a single protuberance extending longtudinally,along the length of the rib intermediate said insulator body and theperipheral edge of the rib, and outermost symmetrical protuberancesalong the peripheral edge of the, rib, symmetrical with respect to the:rib and forrning a groove between one of said outermost theintermediate protuberance.

3. A self-cleaning insulator comprising an elongated body ,of dielectricmaterial having a helical rib integral protuberances and thereonextending along the length of said body, the rib having an upper and alower face and oneach of said faces a single protuberance attendinglongitudinally along i 3,oo3,o22

the length of the rib intermediate said 'nsulator body and ReferencesCited in the file of this patent the peripheral edge'of the rib, the ribhaving outermos't 'UN STATES PATENTS protuberances along the peripheraledge thereof symmetrical with respect to the rib faces and fou'm'nggrooves on 1394392 Gram Jam 1933 said faces between the outermostprotuberances and the 5 ?0155348 Tayq` 1939 intermediate protuberances,and said outermost and nter- FOREIGN P ATENTS mediate protuberances andsaid grooves being disposed 436397 Great Britain Oct 10, 1935 coaxially,and the intermediate protuberances being disposed symmetficauy on said flss France P 1958

